There are more types of rainbows in the world than you may realize. When you see the typical rainbow that forms after a storm, you may think that is all there is to it.
But in truth, there are all sorts of rainbows—some rarer than others. Each type of rainbow is created under different circ*mstances and falls either into primary or secondary types.
Read on to find out more about the different types of rainbows.
Fogbow
A fogbow is a type of rainbow that occurs when fog or a small cloud experience sunlight passing through them. The droplets of moisture from the fog work to diffract that light.
This type of rainbow is usually found in places where the fog in the air is thin. It can also form above any body of water.
Typically, this rainbow consists of blue, white, and red. The majority of a fogbow rainbow is white, with blue appearing on the inside and red appearing at both ends.
Lunar
A lunar rainbow (aka “moonbow”) is another unusual sight. This event occurs on the moon during a lunar month. The moon must be almost fully lit up in order for this type of rainbow to form. When it does, it appears as a white arc.
Lunar rainbows line the moon’s outer rim. They are dull in appearance because the light on the moon is not as bright as the light on the earth.
Multiple Rainbows
One of the rarest forms is multiple, or double, rainbows. They occur when several rainbows form in the same place at the same time. It takes at least one primary rainbow to generate this sight, as well as several other secondary rainbows. There is always space in between each one.
This space is referred to as Alexander’s Band. The name was inspired by an ancient philosopher associated with the forming of these spaces. When sunlight is reflected in raindrops, a double reflection occurs. White light reflects off the colors of the primary rainbow, creating secondary ones.
Twinned
A twinned rainbow is also a rare sight to see. Though they have one base in common, two rainbows are formed, with one being primary and one being secondary. The colors of both rainbows are seen in the same sequence.
When two rain showers occur, the size of the raindrops can lead to the formation of a twinned rainbow. With different shaped and sized raindrops from each storm, one rainbow becomes two. In an even rarer sight, a twinned rainbow can include the formation of as many as three.
Full Circle
In most cases, rainbows are semicircular. Yet on rare occasions, it is possible to spot a full circle rainbow.
This type of rainbow typically occurs in high altitude areas. At lower altitudes, the position of the sun prevents a full circle from being formed.
Anything obstructing the sun also makes it impossible for this type of rainbow to form. When it does, it may include both primary and secondary rainbows.
Supernumerary bow
Supernumerary bows are yet another rare type. It occurs in primary rainbows, acting as another band inside of it. This type is created after the sunlight has hit drops of water 1 millimeter in size or less.
The most unusual thing about supernumerary rainbows is that they don’t use traditional colors. Instead, this type of rainbow features several pastel colors.
Seeing a rainbow—especially one of the rarer types—can feel like a stroke of good luck. But even if you can’t find a rainbow in real life, our diffraction glasses will bring the colors straight to your eyes! They function using the same principles as a rainbow, with the photons in white light breaking into the full spectrum of color when they hit the lens. Find out more on our site!
